The electric grid operator for Texas said record power consumption this summer and an increased chance of energy alerts would allow the operator to take advantage of additional resources if needed to meet demand.
In its preliminary Seasonal Assessment of Resource Adequacy (SARA) for the summer season (June-September), the Electric Reliability Council of Texas (ERCOT) said its peak load forecast of 74,853 MW was based on normal summer peak weather conditions between 2003 and 2017. However, the grid operator expects total resource capacity for this summer to be 78,154 MW.
"Prior to each season, we consider a range of potential risks to determine whether there will be sufficient capacity to meet the expected peak load forecast," ERCOT CEO Bill Magness said. "In all of the scenarios studied, we identified a potential need to call an energy alert at various times this summer."
When ERCOT declares an alert, it can then take advantage of additional resources that are only available during scarcity conditions. These resources include demand response products, resources that are normally set aside to provide operating reserves (including contracted load reduction from some industrial facilities), additional generation or imports from neighboring regions, and voluntary calls for conservation by consumers.
ERCOT’s current planning reserve margin has fallen to a historically low 7.4%, at the same time that electric demand in its territory continues to grow. Between 2016 and this month, the grid operator set 16 monthly peak demand records and all-time system-wide peak demand records in 2016 and 2018.
The reserve margin is lower than the 8.1% it had projected for 2019 in December, when it said that rampant drilling activity in the Permian Basin continued to drive up demand. At that time, ERCOT said the annual growth rate in peak demand in West Texas was forecast to be around 8% through 2023, whereas the grid operator’s annual system-wide load growth rate is 2% during the same time.
The final summer SARA report is to be released in May and would reflect the expected summer weather conditions. In addition to the preliminary summer assessment, ERCOT also issues a final SARA for the spring season, which covers the March-May period. That assessment projected a spring firm peak load forecast of 61,566 MW based on current expectations of weather and was unchanged from the forecast in October.
Subsequent to the release of the preliminary spring SARA forecast, 119 MW of planned gas resources, 227 MW of planned wind resources and 151 MW of planned solar resources entered commercial operations. These capacity values for wind and solar reflect spring peak average capacity contributions. Additionally, 50 MW of planned wind and solar capacity is expected to be available at the start of the spring season, ERCOT said.
The grid operator expects to see 10,564 MW of unit outages based on historical spring outage data from the past three years (starting with 2016), and assumes the high likelihood that the spring peak will occur in May.
“While a significant amount of unit maintenance is conducted during the spring season, much of this maintenance is completed prior to the onset of hotter temperatures (and resulting higher electricity demand) in late May,” the operator said.
ERCOT thus assumes for the most extreme scenario that an extreme April peak demand coincides with average April outage amounts occurring during the peak hours of each weekday.